Hopper door operating and latching assembly



Inventor:

his Attorney 2 Sheets-Sheet 1 Walter L. Floehr W. L. FLOEHR May 2, 1967 HOPPER DOOR OPERATING AND LATCHING ASSEMBLY Filed Feb. 4, 1963 y 2, 1967 w. L. FLOEHR 3,316,859

HOPPER DOOR OPERATING AND LATCHING ASSEMBLY Filed Feb. 4, 1965 2 SheetsSheet 3 Walter L. Floehr his Attorney United States Patent Office 3,316,859 Patented May 2, 1967 3,316,859 HOPPER DOOR OPERATING AND LATCHING ASSEMBLY Walter L. Floehr, Toledo, Ohio, assignor to Unitcast Corporation, Toledo, Ohio, a corporation of Ohio Filed Feb. 4, 1963, Ser. No. 255,849. 14 Claims. (Cl. 105-253) This invention relates generally to railway hopper cars and particularly to door operating assemblies for such cars.

An object of the invention is to provide an improved hopper door operating assembly for operating oppositely opening hopper doors in unison.

Another object of the invention is to provide a hopper door operating assembly which is manually operable without danger to the operator and in an opening operation makes use of inbuilt means by which the safety of the operator is assured, to enable a door stuck to its seat to be freed therefrom.

A further object of the invention is to provide a hopper door operating assembly having a compound operating shaft of which one part is effective to open and close a door and another enables a sealed block by which the door is locked against tampering in closed position readily to be unlocked when it is desired to open the door.

An additional object of the invention is to provide a hopper door operating assembly which is operable from either side of a car and is quick-operating for enabling the lading in a hopper car to be dumped in a minimum of time.

Other objects and advantages of the invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and be illustrated in the accompanying drawings, in which:

FIGURE 1 is a side elevational view of a preferred embodiment of the door operating assembly of the present invention with portions broken away and shown in section to more clearly illustrate certain of the details of the construction;

FIGURE 2 is a vertical sectional view on an enlarged scale taken along lines 2-2 of FIGURE 1;

FIGURE 3 is a fragmentary vertical sectional view on an enlarged scale taken along lines 3-3 of FIGURE 1;

FIGURE 4 is a fragmentary vertical sectional View taken along lines 4-4 of FIGURE 3; and

FIGURE 5 is a fragmentary vertical sectional View taken along lines 5-5 of FIGURE 3.

Referring now in detail to the drawings in which like characters designate like parts, the improved hopper door operating assembly of the present invention is particularly designed for enabling oppositely opening hopper doors to be operated manually in unison from one and preferably either side of a railway hopper car. In the preferred embodiment, illustrated as exemplary of the invention, the assembly, designated as 1, is comprised of a pair or plurality of oppositely opening or swinging hopper doors 2 swingably or pivotally mounted on the underside of a hopper car 3 for swinging or pivoting about parallel horizontal axes spaced longitudinally and disposed transversely of the car. Conveniently, each of the doors 2 is mounted on a pair of trunnions 4 outstanding from opposite sides of a horizontally disposed frame 5 surrounding or encircling and fixed to the side and end sheets 6 and 7, respectively, of a downwardly opening or discharging hopper 8, the preferred frame extending across the car below the center sills 9 and being fixed to the hopper above the hoppers lower extremity.

The illustrated hopper 8 is of the shallow rather than the saw-tooth type but differs from the conventional shallow hopper in having, instead of a single opening, a pair of longitudinally spaced openings or outlets 10, each closable by one of the doors, thus avoiding the usual need for abutment of and close tolerance fit between the adjoining ends of the doors in order to close the hopper. Extending across the car beyond the sides of the center sills 9, the preferred openings 10 are bounded at their far ends and sides by downward extensions of the end and side sheets 7 and 6 of the hopper and at their near ends by the downwardly divergent sides 11 of a ridge sheet or separator 12 of inverted V-shape. For closing these openings, each of the doors 2 has a plate or main part 13 the inner face 14 of which in closed position fits or seats against a seat 15 on the hopper around or bounding the opening and, at opposite sides of the plate, has arms 16 pivoted to and extending radially of or normal to the related trunnions 4.

In the preferred door construction, the pivotal axis of each door is disposed above its opening 10 and positioned, longitudinally of the car, within the longitudinal limits or ends of the opening 10. In addition, the plate 13 of each door is bent or divided longitudinally along a line, which, in the doors closed position, is substantially parallel to and aligned vertically with its pivotal axis, into two continuous but angularly related panels. Of these panels, the inner or front 17 adjoining or continguous to the other door, is disposed substantially horizontally when the door is closed, while the other, outer or rear panel 18, in the same position of the door, slopes upwardly and outwardly or away from the inner panel. While,

when in closed position, the bend between its panels 17 and 18 is in substantially vertical alignment with its pivotal axis, each of the preferred doors 2 has its mass so distributed that in the same position its center of gravity or mass is either in vertical alignment with or, as illustrated, slightly inside or forward of that axis.

Constructed in the above manner, the doors in their open positions indicated in dot-and-dash lines in FIGURE 2 will be positioned rearwardly if their axes and rearwardly of and adjacent the rear ends or boundaries of their openings and on release from those positions, will swing by gravity or of their own weight toward the closed positions shown in solid lines in that figure in which they are positioned beneath their openings and their kinetic energy or momentum will carry them to the latter positions. Conversely, when closed, the doors, on release will have their own weight substantially in balance about their axes and must be driven to their open positions. However, when presented to or in the presence of lading, the downward forces of or exerted by the latter on the inner or front panels 17, since inward or forward of or between the pivotal axes, will tend to swing the doors away from each other toward their open positions and this tendency will be augmented or assisted, rather than opposed, by the forces of the lading on the outer panels 18 by virtue of the latters upward slope or inclination such that the center lines of the forces of the lading upon them also are directed or pass inwardly of or between the pivotal axes. Thus, in an opening operation the forces exerted by lading on both panels urge each door to swing toward open position.

The doors 2 of the preferred bent plate construction have their seats 15 correspondingly configured to enable the discharge openings 10 to be closed and, to enhance the fits between the doors and their seats, it is desirable that each have on and substantially covering the inner face 14 of its plate 13 a liner or pad 19 of rubber or like resilient material for direct engagement with the seat. Bounded on their ends by upturned lips or flanges 20, the preferred doors are reinforced on their outer faces 21 by structural shapes or other suitable reinforcement 22 extending transversely of the doors and contained between and abutting extensions of the arms 16 projecting outwardly beyond the plates 13.

For operating the doors 2, the assembly of this invention includes a compound operating shaft 23, which preferably extends across the car 3 to permit operation from either side, conveniently in the space within the ridge sheet 12 between the discharge openings 10, and is suitably journaled at either end, as by a pair of split bushings 24, one fixed to the outer face of the adjoining side sheet 6 of the hopper below the frame and the other to the inner or confronting face of a mounting flange 25 suspended from the outwardly sloping part above the frame of the same side sheet.

The compound operating shaft 23 is preferably symmetrical about the center line of the car and formed of two independently or relatively rotatable, coaxial or concentric shafts, one an outer or door-operating shaft 26 in the form of a tube, sleeve or pipe and the other an inner or lock-operating or seal-breaking shaft 27, conveniently in the form of a cylindrical rod and housed, contained or received in and projecting beyond opposite ends of the outer shaft. Of the two shafts, the door-operating shaft 26 preferably is drivably connected at both sides of the car to the doors 2 to eliminate twisting of the latter, in each case by a double-armed crank or lever 23, fixed, as by welding, to the shaft outwardly of the doors and having diametrically opposed arms 29, each of which is connected by a link 30 to the adjoining side of one of the doors. Positioned on the operating shaft 27 between the split bushings 24 at its side of the car, the crank 29 and its links 30 are so arranged as to fold together in the closed position of the doors and that the pivotal connection between the crank and each link will be over center or have moved past a line between the axis of the shaft and the pivot of the link on the related door when the latter is in open position. Thus enabled, after moving the doors to open position, to hold them in that position until turned to disturb the over-center disposition of its pivots to the links, the outer or door-operating shaft 26 itself is turned, rotated or moved through one of a pair of operating heads or capstans 31 positioned on opposite sides of the car, each beyond or outwardly of the adjoining mounting flange 25.

Suitably socketed, as at 32, to receive an actuating bar or lever (not shown), each operating head, rather than being fixed to the door-operating shaft 26, is rotatably or fioatably mounted thereon between a coupler or connector 33 and a washer or other suitable retainer or stop 34, the coupler and washer being fixed to the shaft, respectively, inwardly and outwardly of the operating head. Limited or restrained in axial movement relative to the shaft 26 by the coupler 33 and washer 34, the operating head is also limited in rotative movement relative to the shaft by a lost motion connection 35 between it and the coupler. For this purpose, the head or driving member 31 or the coupler or driven member 33, here the head, has an axial socket 36 in which the adjoining end portion of the other member is received and the actual connection is made by a pair of radially aligned and projecting sectoral lugs, each fixed to or rigid or integral with one of the members and one instanding from the socketed member and the other outstanding from the portion of the other member received in the socket.

Serving, respectively, as hammer and anvil, the sectoral lug or tooth 37 on the coupler 33 and the cooperating lug or tooth 38 on the head 31 are preferably of such arcuate extent that the lost or free motion therebetween is substantially equal to the are or angle of movement of the door-operating shaft 26 and the doors 2 is moving the latter between open and closed positions. Except as assisted by the force of the lading, the doors 2 in opening are required to be driven by the turning movement of the door-operating shaft 26 to open position, but, once the over-center relation of the crank 28 and links 39 in that position is eliminated, will swing by gravity or of their own weight substantially to closed position. Consequently, in closing the doors, the only force required to be applied to the operating shaft is that needed to upset or disturb the over-center relation and enable the force of gravity to take over, whereafter the doors will swing closed of themselves and in process turn the operating shaft in the corresponding direction. It is in this turning of the shaft that an operator could be injured by the swinging of the actuating bar, in the absence of the lost motion connection between the head 31 and the coupler 33. However, with the lost motion connection 35 providing lost motion comparable with the angle of movement or rotation of the shaft 26 in movement of the doors from open to closed position, the doors, once released from open position by the force applied to the shaft through the operating head, themselves apply no force through the shaft to the head as they swing to closed position. It, therefore, is feasible for the operator, in a closing operation, to hold onto the actuating bar after applying the force therethrough to release the doors. Another important advantage of the lost motion connection is that it enables the operator to deliver a hammer blow through the adjoining head 31 to the operating shaft 26 and therethrough to the doors 2 in either the open or closed positons of the latter, thus minimizing the strength required to close the door and, in an opening ope-ration, enabling the door to be released from their seats 15 if stuck thereto by a bonding action of the lading or otherwise, without the usual resort to a hammer or pry bar to break the doors loose. Also, as in a closing operation, the doors in an opening operation, once they are free to swing, can swing under the forces of the lading toward open position without imparting movement to head 31 to which the actuating bar is applied. An operator thus is protected by the lost motion connection 35 against injury in opening as well as in closing the doors.

For locking the doors in closed position, there is mounted on the outer face of the mounting flange 25 at one and preferably either side of the car, a mounting bracket 39 on which is pivotally mounted a locking dog, lock or latch 40 overlying and adapted to drop into and be received or seated in a slot, notch or seat 41 in the side of the operating head 31. By positioning the lugs 37 and 38 of the lost motion connection 35 between the head 31 and the coupler 33 circumferentially of the members to which they are fixed such that, when the doors are closed and the locking dog 40 is received in the slot 41 in the operating head 31, the driving or hammer lug 38 on the head will engage or bear against the side of the anvil or driven lug 37 on the coupler against which it acts initially in closing the doors, locking of the operating head against rotation is made effective also to lock the doors in closed position.

To insure against tampering, the operating head 31, dog 40, and mounting bracket 39 are provided with seal holes 42 for conventional scaling in locked position by a wire (not shown) threaded through the holes and having its ends sealed together. In the conventional arrangement, it is necessary to break the seal and unlock the operating mechanism by cutters and a pry bar. However, ;in the assembly of this invention, the means for breaking the seal and unlocking the operating head are 1 inbuilt and can be actuated by the same actuating bar used to actuate the door-operating head 31. These inbullt means are the inner or seal-breaking shaft 27, an operating head 43 riveted or otherwise fixed to either end of that shaft and bifurcated or socketed as at 44 to receive the actuating ba-r (not shown), and a radial cam 45 carried by or fixed to that head and positioned axially to engage and act on an outward extension or finger 46 of the locking dog 40. In the locked position of the assembly presenting to the locking dog 40 a portion of its surface substantially flush with the side of the lockoperating head 43, the cam 45, on rotation of the head, is adapted to act on and cam or lift the dog out of the seal.

lock-operating shaft 27.

slot 41 in the other or door-operating head 31 and in process apply suflicient leverage to the dog to break the Thus unlocking action at one side of the car is duplicated at the other by transmission of the applied force to the cam at the latter side through the inner or While the lock-operating or unlocking shaft 27 and the door-operating shaft 26 are independently rotatable, it is desirable that they also have a lost motion connection 47, as by providing on one or either end of the outer or door-operating shaft an arcuate or sectoral extension 48 projecting or extending outwardly into each of the lock-operating heads 43 and engageable and co-acting with a sectoral lug 49 fixed to or formed integrally with the head, the engagement or co-action of which in the course of an opening and closing operation, insures that, when the doors are closed at the end of the operation, each cam 45 will be positioned in its normal or inoperative position to permit the related dog 40 to be received or seated in its slot 41.

From the above-detailed description, it will be apparent that there has been provided an improved hopper door operating assembly which is manually operable quickly and with a minimum of effort without danger to an operator and not only is effective to release stuck doors but incorporates means for enabling the doors to be unlocked when their operation is desired. It should be understood that the described and disclosed embodiment is merely exemplary of the invention and that all modifications are intended to be included that do not depart from the spirit of the invention or the scope of the appended claims.

Having described my invention, I claim:

1. A door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a discharge opening, comprising a door mounted on said car above said opening for swinging about a horizontal axis between an open position rearwardly of said axis and adjacent an end of said opening to a closed position beneath said openingsaid door in closed position presenting to any lading in said hopper an inner face extending forwardly and rearwardly of and having angularly related portions disposed normal to said axis and constructed and arranged for enabling said lading acting on each portion to exert a door-opening force thereon, and said door in said closed position having the center of gravity thereof so disposed relative to said swinging axis as to be swingable by gravity from open to closed position, an operating shaft mounted on said car and disposed parallel to said axis, means drivably connecting said shaft to said door for swinging thereof between open and closed positions, operating means rotatably mounted on said car concentrically of said shaft, and lost motion means operatively connecting said operating means and shaft, said lost motion means having an arc of lost motion of such extent relative to the arc of swinging of said door between open and closed positions as to enable said door to swing in a closing direction between said positions without imparting movement to said operating means.

2. A door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a discharge opening, comprising a door mounted on said car above said opening for swinging about a horizontal axis between an open position rearwardly of said axis and adjacent an end of said opening to a closed position beneath said opening, said door in closed position presenting to any lading in said hopper an inner face forwardly and rearwardly of and having portions angularly related in a direction normal to said axis and constructed and arranged for enabling said lading acting on each portion to exert a door-opening force thereon, and said door in said closed position having the center of gravity thereof so disposed relative to said swinging axis as to be swingable by gravity from open to closed position, an operating shaft mounted on said car and disposed parallel to said axis, link and lever means drivably connecting said shaft to said door for swinging thereof between open and closed positions on rotation of said shaft, operating means rotatably mounted on said car concentrically of said shaft, and lost motion means operatively connecting said operating means and shaft, said lost motion means having an arc of lost motion of such extent relative to the are of swinging of said door between open and closed positions as to enable said door to swing in a closing direction between said positions without imparting movement to said operating means.

3. A door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a discharge opening, comprising a pair of spaced oppositely swinging doors each for closing one of said openings, said doors being mounted on said car above said openings for swinging relative thereto about laterally spaced parallel axes between open and closed positions, a compound operating shaft extending parallel to said axes, said shaft including an outer shaft link-and-lever connected to each of said doors for swinging thereof between open and closed positions on rotation of said outer shaft and an inner shaft in and extending axially beyond and rotatable relative to said outer shaft, an operating head rotatably mounted on said outer shaft, lost motion means operative- 1y connecting said head and outer shaft and having an arc of lost motion sufficient to enable said doors to swing by gravity between open and closed positions without imparting movement to said head, means mounted on said car and engageable with said head for locking said head against rotation and therethrough said doors in closed position, and means carried by said inner shaft and operative on rotation thereof to act on said locking means and release said head therefrom.

4. A door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a discharge opening, comprising a pair of spaced oppositely swinging doors each for closing one of said openings, said doors being mounted on said car above said openings for swinging relative thereto about laterally spaced parallel axes between open and closed positions, a compound operating shaft extending parallel to said axes, said shaft including an outer shaft link-and-lever connected to each of said doors for swinging thereof between open and closed positions on rotation of said outer shaft and an inner shaft in and extending axially beyond and rotatable relative to said outer shaft, an operating head rotatably mounted on said outer shaft, lost. motion means operatively connecting said head and outer shaft and having an arc of lost motion sufiicient to enable said doors to swing independently between open and closed positions without imparting movement to said head, means mounted on said car and engageable with said head for locking said head against rotation and therethrough said doors in closed position, cam means carried outwardly of said outer shaft by and projecting radially of said inner shaft and operative on rotation of said inner shaft to act on said locking means and release said head therefrom, and a lost motion connection between said outer and inner shafts for moving said cam means to an inoperative position during swinging of said doors from and back to closed position.

5. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a discharge opening thereof, the combination of an operating shaft rotatably mounted on said car and drivably connected to said door for swinging thereof between open and closed positions, means mounted on said car for locking said shaft against operation in the closed position of said door, rotary means carried by said shaft operative in the locked condition thereof to act on said locking means and release said shaft therefrom, and means in the connection between said shaft and connected means for moving said connected means to an inoperative position during'swinging of said door from and back to closed position.

6. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a dis charge opening thereof, the combination of an operating shaft rotatably mounted on said car and drivably -connected to said door for swinging thereof between open and closed positions, means mounted on said car for locking said shaft against operation in the close-d position of said door, and rotary means carried by and rotatable relative to said shaft and operative in the locked condition thereof to act on said locking means and release said shaft therefrom.

7. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a discharge opening thereof, the combination of an operating shaft rotatably mounted on said car and drivably connected to said door for swinging thereof between open and closed positions, means mounted on said car for locking said shaft against operation in the closed position of said door, shaft means rotatably mounted in and projecting beyond said shaft, and rotary means carried by said shaft means outwardly of said shaft and operative in the locked condition of said shaft to act on said locking means and release said shaft therefrom.

8. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a discharge opening thereof, the combination of an outer shaft rotatably mounted on said car and drivably connected to said door for swinging thereof between open and closed positions, an operating head rotatably mounted on an end portion of said outer shaft, an inner shaft rotatably mounted in said outer shaft, a lost motion connection between said outer shaft and head for limiting relative rotation therebetween, means mounted on said car for locking said head against rotation and acting through said lost motion connection for locking said door in closed position, and means carried by said inner shaft outwardly of said outer shaft and operative in the locked condition of said head to act on said locking means and unlock said head and door.

9. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a discharge opening thereof, the combination of an outer shaft rotatably mounted on said car and drivably connected to said door for swinging thereof between open and closed positions, an operating head rotatably mounted on an end portion of said outer shaft, an inner shaft rotatably mounted in said outer shaft, a lost motion connection between said outer shaft and head for limiting relative rotation therebetween, means mounted on said car for locking said head against rotation and acting through said lost motion connection for locking said door in closed position, means carried by said inner shaft outwardly of said outer shaft and operative in the locked condition of said head to act on said locking means and unlock said head and door, and a lost motion connection between said shafts for moving said carried means to an inoperative position during swinging of said door from and back to closed position.

10. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a discharge opening thereof, the combination of an outer shaft rotatably mounted on said car and drivably connected to said door for swinging thereof between open and closed positions, an operating head rotatably mounted on an end portion of said outer shaft, an inner shaft rotatably mounted in said outer shaft, a lost motion connection between said outer shaft and head for limiting relative rotation therebetween, means pivotally mounted on said car above and seatable in said head for locking said head against rotation and therethrough and through said lost motion connection said door in closed position, and cam means fixed to and projecting radially from said inner shaft outwardly of said outer shaft and operative in the locked condition of said head for unseating said locking means therefrom and thereby unlocking said head and door.

11. In a door operating assembly for a railway hopper car having a door swingably mounted for closing a discharge opening thereof, the combination of an outer shaft rotatably mounted on said car and drivably connected to said door for swinging thereof between open and closed positions, an operating head rotatably mounted on an end portion of said outer shaft, an inner shaft rotatably mouted in said outer shaft, a lost motion connection between said outer shaft and head for limiting relative rotation therebetween, means pivotally mounted on said car above and seatable in said head for locking said head against rotation and therethrough and through said lost motion connection said door in closed position, and a lost motion connection between said head and inner shaft for moving said cam means to an inoperative position during swinging of said door from and back to closed position.

12. In a door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a discharge opening, a door mounted on said car above said opening for swinging about a horizontal axis from an open position and beyond a boundary of said opening to a closed position beneath said opening, said door in closed position having the center of gravity thereof so disposed relative to said swinging axis as to be swingable of its own weight from open to closed position, and said door in closed position presentingto any lading in said hopper an inner face having portions angularly related in a direction normal to said axis and extending one forwardly and another rearwardly of said axis, said portions being constructed and arranged for enabling said lading to exert on each thereof in said closed position a force urging said door toward open position.

13. In a door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a discharge opening, comprising a door mounted on said car above said opening for swinging vertically from an open position rearwardly of said opening to a closed position therebeneath, said door in closed position having the swinging axis and center of gravity thereof so relatively disposed as to be swingable by gravity from open to closed position, a resilient pad on an inner face of said door and engageable in the closed position thereof with a seat on said hopper about said opening, said inner face extending forwardly and rearwardly of the swinging axis of said door and in said closed position presenting to any lading in said hopper portions angularly related in a direction normal to said axis and constructed and arranged for enabling lading acting on each thereof to exert a force urging said door toward open position, and means mounted on said car and drivably connected to said door for enabling said door to be swung to and releasably held in open position.

14. A door operating assembly for a railway hopper car having a hopper dischargeable downwardly through a pair of spaced discharge openings, comprising a frame fixed to and extending about said hopper above said opening, a pair of doors mounted on said frame for swinging in opposite directions about laterally spaced parallel horizontal axes each between a closed position closing and an open position opening one of said openings, an operating shaft mounted on said car between said openings and rotatable about an axis parallel to the swinging axes of said doors, said operating shaft including an outer shaft and an inner shaft rotatable relative to and projecting beyond ends of said outer shaft, a pair of axially spaced double-armed levers fixed to said outer shaft beyond opposite sides of said doors, a link connecting each side of each door to an arm of the adjoining lever for swinging said doors between open and closed positions on rotation of said outer shaft, head means rotatably mounted on said outer shaft, lost motion means drivably connecting said head means to said outer shaft and having an arc of lost motion substantially equal to the arc of movement of said doors between open and closed positions, means mounted on said -car and seatable in said head means for locking said head means against rotation and said doors in closed position, and means fixed to said inner shaft and operative on rotation thereof to unseat said locking means from said head means.

References Cited by the Examiner UNITED STATES PATENTS 567,942 9/ 1896 Hendrick 222-425 746,519 12/1903 Johnson 105-290 X 914,242 3/ 1909 Campbell 105-253 1,021,351 3/1912 Christianson 105-311 Zimrner 105-291 Hillman 105-313 OConnor 105-311 Batho 105-310 Harrington 105-424 Hull 105-282 Lunde 105-240 Taggart 105-283 X 10 ARTHUR L. LA POINT, Primary Examiner.

LEO QUACKENBUSH, EUGENE G. BOTZ, Examiners. H. BELTRAN, Assistant Examiner. 

1. A DOOR OPERATING ASSEMBLY FOR A RAILWAY HOPPER CAR HAVING A HOPPER DISCHARGEABLE DOWNWARDLY THROUGH A DISCHARGE OPENING, COMPRISING A DOOR MOUNTED ON SAID CAR ABOVE SAID OPENING FOR SWINGING ABOUT A HORIZONTAL AXIS BETWEEN AN OPEN POSITION REARWARDLY OF SAID AXIS AND ADJACENT AN END OF SAID OPENING TO A CLOSED POSITION BENEATH SAID OPENING, SAID DOOR IN CLOSED POSITION PRESENTING TO ANY LADING IN SAID HOPPER AN INNER FACE EXTENDING FORWARDLY AND REARWARDLY OF AND HAVING ANGULARLY RELATED PORTIONS DISPOSED NORMAL TO SAID AXIS AND CONSTRUCTED AND ARRANGED FOR ENABLING SAID LADING ACTING ON EACH PORTION TO EXERT A DOOR-OPENING FORCE THEREON, AND SAID DOOR IN SAID CLOSED POSITION HAVING THE CENTER OF GRAVITY THEREOF SO DISPOSED RELATIVE TO SAID SWINGING AXIS AS TO BE SWINGABLE BY GRAVITY FROM OPEN TO CLOSED POSITION, AN OPERATING SHAFT MOUNTED ON SAID CAR AND DISPOSED PARALLEL TO SAID AXIS, MEANS DRIVABLY CONNECTING SAID SHAFT TO SAID DOOR FOR SWINGING THEREOF BETWEEN OPEN AND CLOSED POSITIONS, OPERATING MEANS ROTATABLY MOUNTED ON SAID CAR CONCENTRICALLY OF SAID SHAFT, AND LOST MOTION MEANS OPERATIVELY CONNECTING SAID OPERATING MEANS AND SHAFT, SAID LOST MOTION MEANS HAVING AN ARC OF LOST MOTION OF SUCH EXTENT RELATIVE TO THE ARC OF SWINGING OF SAID DOOR BETWEEN OPEN AND CLOSED POSITIONS AS TO ENABLE SAID DOOR TO SWING IN A CLOSING DIRECTION BETWEEN SAID POSITIONS WITHOUT IMPARTING MOVEMENT TO SAID OPERATING MEANS. 